Having graduated in medicine from Kings College in London, Guy practiced in Opthalmology and neurosurgery before moving to a career in business. This has included roles in operations as well as finance. His experience includes drug development at Eli Lilly and working in Healthcare investment banking first as a stock analyst with Barclays de Zoete Wedd and then in mergers and acquisitions with JPMorgan. Investment banking highlights include the demerger of ICI and IPO of Zeneca (now AstraZeneca) and the Wellcome £2.3bn stock offering (the largest in UK corporate history at the time). He subsequently became Chief Executive of Cancer Research Ventures, the technology transfer company for the Cancer Research Campaign. Since then he has been Chairman of Cambridge Cognition Ltd and Chief Executive of Deontics Ltd. which he cofounded and spun out from the University of Oxford. He has been a Trustee of the Royal Society of Medicine and holds an MBA from INSEAD.